/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package com.googlecode.bluetools.dom4j.rule;

import java.util.HashMap;
import java.util.Map;

import com.googlecode.bluetools.dom4j.Attribute;
import com.googlecode.bluetools.dom4j.Document;
import com.googlecode.bluetools.dom4j.Element;
import com.googlecode.bluetools.dom4j.Node;

/**
 * <p>
 * <code>Mode</code> manages a number of RuleSet instances for the mode in a stylesheet. It is responsible for finding
 * the correct rule for a given DOM4J Node using the XSLT processing model uses the smallest possible RuleSet to reduce
 * the number of Rule evaluations.
 * </p>
 * 
 * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
 * @version $Revision: 1.1 $
 */
public class Mode {
	private RuleSet[] ruleSets = new RuleSet[Pattern.NUMBER_OF_TYPES];

	/** Map of exact (local) element names to RuleSet instances */
	private Map elementNameRuleSets;

	/** Map of exact (local) attribute names to RuleSet instances */
	private Map attributeNameRuleSets;

	public Mode() {
	}

	/**
	 * Runs the actions associated with the given node
	 * 
	 * @param node DOCUMENT ME!
	 * 
	 * @throws Exception DOCUMENT ME!
	 */
	public void fireRule(Node node) throws Exception {
		if (node != null) {
			Rule rule = getMatchingRule(node);

			if (rule != null) {
				Action action = rule.getAction();

				if (action != null) {
					action.run(node);
				}
			}
		}
	}

	public void applyTemplates(Element element) throws Exception {
		for (int i = 0, size = element.attributeCount(); i < size; i++) {
			Attribute attribute = element.attribute(i);
			fireRule(attribute);
		}

		for (int i = 0, size = element.nodeCount(); i < size; i++) {
			Node node = element.node(i);
			fireRule(node);
		}
	}

	public void applyTemplates(Document document) throws Exception {
		for (int i = 0, size = document.nodeCount(); i < size; i++) {
			Node node = document.node(i);
			fireRule(node);
		}
	}

	public void addRule(Rule rule) {
		int matchType = rule.getMatchType();
		String name = rule.getMatchesNodeName();

		if (name != null) {
			if (matchType == Node.ELEMENT_NODE) {
				elementNameRuleSets = addToNameMap(elementNameRuleSets, name, rule);
			}
			else if (matchType == Node.ATTRIBUTE_NODE) {
				attributeNameRuleSets = addToNameMap(attributeNameRuleSets, name, rule);
			}
		}

		if (matchType >= Pattern.NUMBER_OF_TYPES) {
			matchType = Pattern.ANY_NODE;
		}

		if (matchType == Pattern.ANY_NODE) {
			// add rule to all other RuleSets if they exist
			for (int i = 1, size = ruleSets.length; i < size; i++) {
				RuleSet ruleSet = ruleSets[i];

				if (ruleSet != null) {
					ruleSet.addRule(rule);
				}
			}
		}

		getRuleSet(matchType).addRule(rule);
	}

	public void removeRule(Rule rule) {
		int matchType = rule.getMatchType();
		String name = rule.getMatchesNodeName();

		if (name != null) {
			if (matchType == Node.ELEMENT_NODE) {
				removeFromNameMap(elementNameRuleSets, name, rule);
			}
			else if (matchType == Node.ATTRIBUTE_NODE) {
				removeFromNameMap(attributeNameRuleSets, name, rule);
			}
		}

		if (matchType >= Pattern.NUMBER_OF_TYPES) {
			matchType = Pattern.ANY_NODE;
		}

		getRuleSet(matchType).removeRule(rule);

		if (matchType != Pattern.ANY_NODE) {
			getRuleSet(Pattern.ANY_NODE).removeRule(rule);
		}
	}

	/**
	 * Performs an XSLT processing model match for the rule which matches the given Node the best.
	 * 
	 * @param node is the DOM4J Node to match against
	 * 
	 * @return the matching Rule or no rule if none matched
	 */
	public Rule getMatchingRule(Node node) {
		int matchType = node.getNodeType();

		if (matchType == Node.ELEMENT_NODE) {
			if (elementNameRuleSets != null) {
				String name = node.getName();
				RuleSet ruleSet = (RuleSet) elementNameRuleSets.get(name);

				if (ruleSet != null) {
					Rule answer = ruleSet.getMatchingRule(node);

					if (answer != null) {
						return answer;
					}
				}
			}
		}
		else if (matchType == Node.ATTRIBUTE_NODE) {
			if (attributeNameRuleSets != null) {
				String name = node.getName();
				RuleSet ruleSet = (RuleSet) attributeNameRuleSets.get(name);

				if (ruleSet != null) {
					Rule answer = ruleSet.getMatchingRule(node);

					if (answer != null) {
						return answer;
					}
				}
			}
		}

		if ((matchType < 0) || (matchType >= ruleSets.length)) {
			matchType = Pattern.ANY_NODE;
		}

		Rule answer = null;
		RuleSet ruleSet = ruleSets[matchType];

		if (ruleSet != null) {
			// try rules that match this kind of node first
			answer = ruleSet.getMatchingRule(node);
		}

		if ((answer == null) && (matchType != Pattern.ANY_NODE)) {
			// try general rules that match any kind of node
			ruleSet = ruleSets[Pattern.ANY_NODE];

			if (ruleSet != null) {
				answer = ruleSet.getMatchingRule(node);
			}
		}

		return answer;
	}

	/**
	 * DOCUMENT ME!
	 * 
	 * @param matchType DOCUMENT ME!
	 * 
	 * @return the RuleSet for the given matching type. This method will never return null, a new instance will be
	 *         created.
	 */
	protected RuleSet getRuleSet(int matchType) {
		RuleSet ruleSet = ruleSets[matchType];

		if (ruleSet == null) {
			ruleSet = new RuleSet();
			ruleSets[matchType] = ruleSet;

			// add the patterns that match any node
			if (matchType != Pattern.ANY_NODE) {
				RuleSet allRules = ruleSets[Pattern.ANY_NODE];

				if (allRules != null) {
					ruleSet.addAll(allRules);
				}
			}
		}

		return ruleSet;
	}

	/**
	 * Adds the Rule to a RuleSet for the given name.
	 * 
	 * @param map DOCUMENT ME!
	 * @param name DOCUMENT ME!
	 * @param rule DOCUMENT ME!
	 * 
	 * @return the Map (which will be created if the given map was null
	 */
	protected Map addToNameMap(Map map, String name, Rule rule) {
		if (map == null) {
			map = new HashMap();
		}

		RuleSet ruleSet = (RuleSet) map.get(name);

		if (ruleSet == null) {
			ruleSet = new RuleSet();
			map.put(name, ruleSet);
		}

		ruleSet.addRule(rule);

		return map;
	}

	protected void removeFromNameMap(Map map, String name, Rule rule) {
		if (map != null) {
			RuleSet ruleSet = (RuleSet) map.get(name);

			if (ruleSet != null) {
				ruleSet.removeRule(rule);
			}
		}
	}
}

/*
 * Redistribution and use of this software and associated documentation ("Software"), with or without modification, are
 * permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions must also contain a
 * copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
 * following disclaimer in the documentation and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived from this Software without prior written
 * permission of MetaStuff, Ltd. For written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may "DOM4J" appear in their names without prior
 * written permission of MetaStuff, Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
